scholarly journals Experimental Studies on Frozen Soil

2021 ◽  
Author(s):  
Kshitij Gaur ◽  
Anil Kumar Sahu
Keyword(s):  
Room Temperature ◽  
Void Ratio ◽  
Experimental Studies ◽  
Soil Surface ◽  
Negative Temperature ◽  
Research Data ◽  
Frozen Soil ◽  
Soil Parameters ◽  
Frozen Soils ◽  
A Site

Abstract Various studies have been carried out for soils at normal room temperature but the studies on frozen soils are meagre. For every construction, soil investigation is the most important and the primary step for a site. For constructions at normal room temperature, there is plenty of experimentation and research data on soil is available. But lack of research data for colder regions, where the ambient temperature is below zero degrees Celsius for most of the time. It is therefore the need to study soil under the iced condition to get a better idea about the behaviour of frozen soils. There is little research on the construction and mechanical behaviour of frozen soil but no study on the very basic parameters like void ratio, bulk density, porosity, and the degree of freezing and how these parameters change as the soil temperature changes from normal room temperature to negative values. The main emphasis is on the study and experimentation of frozen soil and the formulation of different relationships between individual soil parameters at various temperatures. The methodology used is to model the soil surface (open grounds in colder regions) by taking sand as the soil after sieving. The model samples are taken into beakers with different bulk densities to replicate real site conditions in the freezer. Then by calculating factors like density, porosity, void ratio, etc at negative temperature (-5, -10, -15, -20 degree Celsius) and forming a relationship with the same parameters as that on room temperature. The experimental data obtained is used in “Eureqa software” that will utilize the input so provided and will find mathematical relations that exist in the soil parameters.

scholarly journals Experimental Studies on Frozen Soil

2021 ◽  
Author(s):  
Kshitij Gaur ◽  
Anil Kumar Sahu
Keyword(s):  
Room Temperature ◽  
Void Ratio ◽  
Experimental Studies ◽  
Soil Surface ◽  
Negative Temperature ◽  
Research Data ◽  
Frozen Soil ◽  
Soil Parameters ◽  
Frozen Soils ◽  
A Site

Abstract Various studies have been carried out for soils at normal room temperature but the studies on frozen soils are meagre. For every construction, soil investigation is the most important and the primary step for a site. For constructions at normal room temperature, there is plenty of experimentation and research data on soil is available. But lack of research data for colder regions, where the ambient temperature is below zero degrees Celsius for most of the time. It is therefore the need to study soil under the iced condition to get a better idea about the behaviour of frozen soils. There is little research on the construction and mechanical behaviour of frozen soil but no study on the very basic parameters like void ratio, bulk density, porosity, and the degree of freezing and how these parameters change as the soil temperature changes from normal room temperature to negative values. The main emphasis is on the study and experimentation of frozen soil and the formulation of different relationships between individual soil parameters at various temperatures. The methodology used is to model the soil surface (open grounds in colder regions) by taking sand as the soil after sieving. The model samples are taken into beakers with different bulk densities to replicate real site conditions in the freezer. Then by calculating factors like density, porosity, void ratio, etc at negative temperature (-5, -10, -15, -20 degree Celsius) and forming a relationship with the same parameters as that on room temperature. The experimental data obtained is used in “Eureqa software” that will utilize the input so provided and will find mathematical relations that exist in the soil parameters.

scholarly journals Experimental Studies on Frozen Soil

2021 ◽  
Author(s):  
Kshitij Gaur ◽  
Anil Kumar Sahu
Keyword(s):  
Room Temperature ◽  
Void Ratio ◽  
Experimental Studies ◽  
Soil Surface ◽  
Negative Temperature ◽  
Research Data ◽  
Frozen Soil ◽  
Soil Parameters ◽  
Frozen Soils ◽  
A Site

Abstract Various studies have been carried out for soils at normal room temperature but the studies on frozen soils are meagre. For every construction, soil investigation is the most important and the primary step for a site. For constructions at normal room temperature, there is plenty of experimentation and research data on soil is available. But lack of research data for colder regions, where the ambient temperature is below zero degrees Celsius for most of the time. It is therefore the need to study soil under the iced condition to get a better idea about the behaviour of frozen soils. There is little research on the construction and mechanical behaviour of frozen soil but no study on the very basic parameters like void ratio, bulk density, porosity, and the degree of freezing and how these parameters change as the soil temperature changes from normal room temperature to negative values. The main emphasis is on the study and experimentation of frozen soil and the formulation of different relationships between individual soil parameters at various temperatures. The methodology used is to model the soil surface (open grounds in colder regions) by taking sand as the soil after sieving. The model samples are taken into beakers with different bulk densities to replicate real site conditions in the freezer. Then by calculating factors like density, porosity, void ratio, etc at negative temperature (-5, -10, -15, -20 degree Celsius) and forming a relationship with the same parameters as that on room temperature. The experimental data obtained is used in “Eureqa software” that will utilize the input so provided and will find mathematical relations that exist in the soil parameters.

scholarly journals Experimental Studies on Frozen Soil

2021 ◽  
Author(s):  
Kshitij Gaur ◽  
Anil Kumar Sahu
Keyword(s):  
Room Temperature ◽  
Void Ratio ◽  
Experimental Studies ◽  
Soil Surface ◽  
Negative Temperature ◽  
Research Data ◽  
Frozen Soil ◽  
Soil Parameters ◽  
Frozen Soils ◽  
Zero Degree

Abstract Various studies have been carried out for soils at normal room temperature but the studies on frozen soils are meagre. For every construction, soil investigation is the most important and the primary step for a site. For constructions at normal room temperature, there are plenty of experimentation and research data on soil is available. But lack of research data for colder regions, where the ambient temperature is below zero degree Celsius for most of the time. It is therefore the need to study soil under iced condition to get a better idea about the behaviour of frozen soils. There are few research on construction and mechanical behaviour of frozen soil but no study on the very basic parameters of like void ratio, bulk density, porosity, and the degree of freezing and how these parameters change as the soil temperature changes from normal room temperature to negative values. The main emphasis is on the study and experimentation on frozen soil and to formulate different relationships between individual soil parameters at various temperatures. The methodology used is to model the soil surface (open grounds in colder regions) by taking sand as the soil after sieving. The model samples are taken into beakers with different bulk densities to replicate real site condition in the freezer. Then by calculating factors like density, porosity, void ratio, etc at negative temperature (-5, -10, -15, -20 degree Celsius) and forming relationship with same parameters with that on room temperature. The experimental data obtained is used in “Eureqa software” that will utilize the input so provided and will find mathematical relation that exist in the soil parameters.

scholarly journals Experimental Studies on Frozen Soil

2021 ◽  
Author(s):  
Kshitij Gaur ◽  
Anil Kumar Sahu
Keyword(s):  
Room Temperature ◽  
Void Ratio ◽  
Experimental Studies ◽  
Soil Surface ◽  
Negative Temperature ◽  
Research Data ◽  
Frozen Soil ◽  
Soil Parameters ◽  
Frozen Soils ◽  
Zero Degree

Abstract Various studies have been carried out for soils at normal room temperature but the studies on frozen soils are meagre. For every construction, soil investigation is the most important and the primary step for a site. For constructions at normal room temperature, there are plenty of experimentation and research data on soil is available. But lack of research data for colder regions, where the ambient temperature is below zero degree Celsius for most of the time. It is therefore the need to study soil under iced condition to get a better idea about the behaviour of frozen soils. There are few research on construction and mechanical behaviour of frozen soil but no study on the very basic parameters of like void ratio, bulk density, porosity, and the degree of freezing and how these parameters change as the soil temperature changes from normal room temperature to negative values. The main emphasis is on the study and experimentation on frozen soil and to formulate different relationships between individual soil parameters at various temperatures. The methodology used is to model the soil surface (open grounds in colder regions) by taking sand as the soil after sieving. The model samples are taken into beakers with different bulk densities to replicate real site condition in the freezer. Then by calculating factors like density, porosity, void ratio, etc at negative temperature (-5, -10, -15, -20 degree Celsius) and forming relationship with same parameters with that on room temperature. The experimental data obtained is used in “Eureqa software” that will utilize the input so provided and will find mathematical relation that exist in the soil parameters.

Experimental Studies of Pipeline Uplift Resistance in Frozen Ground

2004 ◽  
Author(s):  
Bill Liu ◽  
Jack Crooks ◽  
J. F. (Derick) Nixon ◽  
Joe Zhou
Keyword(s):  
Experimental Studies ◽  
Soil Surface ◽  
Mechanical Tests ◽  
Frozen Soil ◽  
Frost Heave ◽  
Frozen Ground ◽  
Frozen Soils ◽  
Uplift Resistance ◽  
Load Displacement ◽  
The Impact

A buried pipeline is subject to a variety of internal and external loads, one of which is the load induced by relative movements between the pipeline and the surrounding soils. Frost heave is one of the potential mechanisms that induce the relative movement for buried pipelines of chilled gas. The magnitude of the loads due to frost heave depends upon the amount of heaving and the load-displacement characteristics of the surrounding frozen soils, i.e., the uplift resistance of the frozen soils. Under the sponsorship of Pipeline Research Council International (PRCI), laboratory uplift tests have been carried out to study the load-displacement characteristics of a frozen soil and to assess the impact of loading rate, ice content and freezing direction. In addition to the measurements of the load and displacement of the pipe, deformations of the soil surface were also monitored at various locations. Parallel to the uplift tests, a series of laboratory geo-mechanical tests were conducted to define stiffness, tensile strain limits and time-dependent behavior of the frozen soil. Examples of the uplift test results are presented in the paper, together with detailed descriptions of soil material and test conditions. It is noted that quantitative data on uplift resistance are considered proprietary and will not be presented in this paper; however, detailed data may be obtained from technical publications of PRCI. Observations during the test with respect to the development of cracks in the frozen soil will be discussed. The load-displacement relationships measured in the uplift tests, together with the geo-mechanical properties of the frozen soil, will be used to the development and calibration of a numerical model, which will be presented in a separate technical paper to IPC2004.

Determining the efficiency of functioning of systems of temperature stabilization of soils with horizontal evaporator filled with different refrigerants

2019 ◽  
Vol 5 (4) ◽  
pp. 37-57
Author(s):  
Alexey A. Ishkov ◽  
Anatoly A. Gubarkov ◽  
Gennady V. Anikin
Keyword(s):  
Carbon Dioxide ◽  
Soil Temperature ◽  
Negative Temperature ◽  
Frozen Soil ◽  
Temperature Fields ◽  
Positive Temperature ◽  
Stabilization System ◽  
Temperature Stabilization ◽  
Simultaneous Exposure ◽  
Frozen Soils

The construction of buildings and structures in the zones of distribution of frozen soils follows the principle I. The bearing capacity of frozen soils significantly depends on their value of negative temperature. When thawed, such soils shrink, which negatively affects the objects built on them. To prevent this, temperature stabilization systems for frozen soils are used. Simultaneous accounting of the thermal effect on the frozen soil of an engineering object, as well as the temperature stabilization system of soils, is a difficult task, the accuracy of determining the strength characteristics of the soil will depend on the correctness of its solution. This paper presents calculations of the temperature fields of frozen soils with simultaneous exposure to an object with intense heat (RVS with hot oil) and soil temperature stabilization system of the horizontal natural-acting tubular system (GET) type. The calculations follow the previously developed mathematical model of the temperature stabilization system with a horizontal evaporator. The authors consider the efficiency of the operation of the GET system charged with different refrigerants (ammonia and carbon dioxide) for different geocryological subzones of Western Siberia. Particular attention should be paid to the fact that the soil was initially at a close to positive temperature (−0,1 °C), but after calculating for 10 years, the entire soil mass around the evaporation part of the temperature stabilization system froze because of the soil temperature stabilization system. Systems charged with carbon dioxide showed better work efficiency. This is due to two factors: a lower value of the lower critical heat load, which gives more working days per year relative to the system charged with ammonia; and the evaporative part of the system on carbon dioxide, which has the average temperature 1 °C lower than ammonia systems. The results show that carbon dioxide as the heat carrier for the GET system is the most effective.

Study on Lateral Earth Pressure Coefficient at Rest for Frozen Soils

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Xiaoliang Yao ◽  
Jilin Qi ◽  
Fan Yu
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
Negative Temperature ◽  
Frozen Soil ◽  
Dominant Factor ◽  
Frozen Soils ◽  
Testing Conditions ◽  
Triaxial Apparatus ◽  
Lateral Earth Pressure ◽  
Earth Pressure Coefficient

The lateral earth pressure coefficient at rest, K0, is an important parameter in geotechnical engineering. There have been many studies for unfrozen soils; however, this is not the case for frozen soils, which impedes reasonable calculation concerning cold regions engineering. This paper introduces a novel triaxial apparatus for frozen soils with reference to that for unfrozen soils. The device is capable of performing experiments on frozen soil samples with K0 status under precisely controlled negative temperature. Two soils along the Qinghai-Tibetan highway are taken as study objects. K0 experiments are carried out with the apparatus and K0 is obtained under different testing conditions. It is found that temperature is a dominant factor in influencing K0 of frozen soils, while stress state and soil type should also be taken into account.

scholarly journals Ab Initio Study of the Effect of Mono-Vacancies on the Metastability of Ga-Stabilized δ-Pu

2020 ◽  
Vol 10 (21) ◽  
pp. 7628
Author(s):  
Sarah C. Hernandez ◽  
Franz J. Freibert
Keyword(s):  
First Principles ◽  
Room Temperature ◽  
Experimental Studies ◽  
Tetragonal Distortion ◽  
Ab Initio Study ◽  
Α Phase ◽  
Fcc Lattice ◽  
Δ Phase ◽  
A Site ◽  
Electronic Behavior

Most experimental studies on metallic Pu are on the room temperature monoclinic α-phase or the fcc Ga stabilized δ-phase. Stabilized δ-phase Pu-Ga alloys are metastable and exhibit a martensitic phase transformation to α’-phase at low temperatures, or applied shear, with concentrations lower than three atomic percent Ga. By using first principles, we explore the metastability of δ-phase by investigating the structural and electronic behavior induced by Ga alloying and by a mono-vacancy point defect. We find that a site substitutional Ga induces a tetragonal distortion in the lattice affected by hybridization of Ga 4p and Pu 6d states. With the addition of a mono-vacancy, a monoclinic or tetragonal distortion forms locally (dependent on its distance from Ga), and decoupling of the Pu 5f and 6d states and broadening of the 6d states occurs. This response enables hybridization of Pu 6d with the Ga 4p states affecting the mono-vacancy formation energy. Thus, stabilization of the fcc lattice correlates with hybridization of Pu 6d states with Ga 4p states, and this becomes more evident in the presence of a mono-vacancy.

scholarly journals Development of Fragility Curves for Piping and Slope Stability of River Levees

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 738
Author(s):  
Nicola Rossi ◽  
Mario Bačić ◽  
Meho Saša Kovačević ◽  
Lovorka Librić
Keyword(s):  
Slope Stability ◽  
Fragility Curves ◽  
Safety Margin ◽  
Water Levels ◽  
Flood Event ◽  
Soil Parameters ◽  
Design Code ◽  
A Site ◽  
Insight Into

The design code Eurocode 7 relies on semi-probabilistic calculation procedures, through utilization of the soil parameters obtained by in situ and laboratory tests, or by the means of transformation models. To reach a prescribed safety margin, the inherent soil parameter variability is accounted for through the application of partial factors to either soil parameters directly or to the resistance. However, considering several sources of geotechnical uncertainty, including the inherent soil variability, measurement error and transformation uncertainty, full probabilistic analyses should be implemented to directly consider the site-specific variability. This paper presents the procedure of developing fragility curves for levee slope stability and piping as failure mechanisms that lead to larger breaches, where a direct influence of the flood event intensity on the probability of failure is calculated. A range of fragility curve sets is presented, considering the variability of levee material properties and varying durations of the flood event, thus providing crucial insight into the vulnerability of the levee exposed to rising water levels. The procedure is applied to the River Drava levee, a site which has shown a continuous trend of increased water levels in recent years.

scholarly journals Effects of preferential flow on snowmelt partitioning and groundwater recharge in frozen soils

2019 ◽  
Vol 23 (12) ◽  
pp. 5017-5031 ◽  
Author(s):  
Aaron A. Mohammed ◽  
Igor Pavlovskii ◽  
Edwin E. Cey ◽  
Masaki Hayashi
Keyword(s):  
Soil Moisture ◽  
Groundwater Recharge ◽  
Preferential Flow ◽  
Frozen Soil ◽  
Time Lags ◽  
Runoff Generation ◽  
Frozen Ground ◽  
Soil Matrix ◽  
Frozen Soils ◽  
Flow Through

Abstract. Snowmelt is a major source of groundwater recharge in cold regions. Throughout many landscapes snowmelt occurs when the ground is still frozen; thus frozen soil processes play an important role in snowmelt routing, and, by extension, the timing and magnitude of recharge. This study investigated the vadose zone dynamics governing snowmelt infiltration and groundwater recharge at three grassland sites in the Canadian Prairies over the winter and spring of 2017. The region is characterized by numerous topographic depressions where the ponding of snowmelt runoff results in focused infiltration and recharge. Water balance estimates showed infiltration was the dominant sink (35 %–85 %) of snowmelt under uplands (i.e. areas outside of depressions), even when the ground was frozen, with soil moisture responses indicating flow through the frozen layer. The refreezing of infiltrated meltwater during winter melt events enhanced runoff generation in subsequent melt events. At one site, time lags of up to 3 d between snow cover depletion on uplands and ponding in depressions demonstrated the role of a shallow subsurface transmission pathway or interflow through frozen soil in routing snowmelt from uplands to depressions. At all sites, depression-focused infiltration and recharge began before complete ground thaw and a significant portion (45 %–100 %) occurred while the ground was partially frozen. Relatively rapid infiltration rates and non-sequential soil moisture and groundwater responses, observed prior to ground thaw, indicated preferential flow through frozen soils. The preferential flow dynamics are attributed to macropore networks within the grassland soils, which allow infiltrated meltwater to bypass portions of the frozen soil matrix and facilitate both the lateral transport of meltwater between topographic positions and groundwater recharge through frozen ground. Both of these flow paths may facilitate preferential mass transport to groundwater.

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